<html>
   <head>
      <meta http-equiv="Content-Type" content="text/html; charset=utf-8">
   </head>
   <body>
      <form action="forward" method="post" >
         <input type="text" name="username"/><br>
         <input type="file" name="file" id="file"/><br>
         <select name="testClass">
             <option value="1">ServletConfig</option>
             <option value="2">ServletContext</option>
             <option value="3">ServletRequest</option>
             <option value="4">ServletResponse</option>
             <option value="5">HttpServletRequest</option>
             <option value="6">HttpServletResponse</option>
             <option value="7">HttpSession</option>
             <option value="9">Cookie</option>
         </select><br>
         <input type="submit" value="提交"/>
      </form>
   </body>
</html>